Memantine Sandoz (Memantine Hydrochloride)

Memantine is an NMDA‑receptor antagonist used in the management of Alzheimer’s disease, a neurodegenerative disorder affecting cognition and function.

• Moderate to severe Alzheimer’s disease: improves cognition, daily functioning and may slow functional decline.
• Alzheimer’s‑related behavioral symptoms: may reduce agitation and aggression in some patients.
• Cognitive impairment due to Alzheimer’s: helps maintain memory and orientation abilities.

• Memantine acts as a non‑competitive antagonist at the N‑methyl‑D‑aspartate (NMDA) receptor, binding to the receptor‑associated ion channel at a site distinct from the glutamate binding site. By blocking excessive calcium influx caused by prolonged glutamate activation, it reduces excitotoxic neuronal injury while preserving normal synaptic transmission, thereby supporting neuronal survival in Alzheimer’s disease.

Memantine is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Dizziness: sensation of light‑headedness or unsteadiness.
• Headache: mild to moderate pain in the head region.
• Constipation: reduced bowel movements or hard stools.
• Fatigue: feeling unusually tired or low in energy.
• Nausea: upset stomach or urge to vomit.

Serious or Rare Side Effects

• Seizures: convulsive episodes requiring immediate medical attention.
• Severe allergic reaction: rash, swelling, breathing difficulty.
• Hallucinations or psychosis: visual or auditory disturbances.
• Cardiac arrhythmia: irregular heart rhythm.
• Suicidal thoughts: emergence of depressive or suicidal ideation.

Before initiating Memantine, clinicians should consider several safety factors.

• Renal impairment: assess kidney function and adjust dose if needed.
• Hepatic impairment: monitor liver enzymes and consider dose modification.
• History of seizures: use with caution and monitor for new seizure activity.
• Concomitant NMDA antagonists: avoid combined use to reduce neurotoxicity risk.
• Pregnancy and lactation: safety not established; weigh potential benefits against risks.
• Store at ambient temperature: keep in original packaging, protect from moisture and direct sunlight.

Memantine may interact with other medicines, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• Amantadine or other NMDA antagonists: increased risk of neurotoxic effects.
• Strong CYP450 inhibitors (e.g., ketoconazole): may raise plasma levels, though metabolism is limited.

Moderate Interactions (Monitor Closely)

• NSAIDs: may increase risk of edema or hypertension.
• Diuretics: enhanced dizziness or hypotension.
• Antihypertensives: possible additive blood pressure lowering.
• Anticholinergic agents: may worsen cognitive impairment.